Many tablets as medicines have conventionally had printed codes for identification of the medicines. An identifying code printed on a tablet is typically a company code representing a manufacturer or a product code for discriminating a product. Such an identifying code is used mainly for preparation of a medicine at a medical institution or pharmacy. To prevent mistaken administration of a tablet (to prevent mistaken administration of a combination of an antihypertensive and a vasopressor, for example), a tablet may be given an indication that facilitates clear recognition of the tablet by a patient. Further, there has also been a desire to assign a number to a tablet for the purpose of traceability of medicine.
The aforementioned identifying code, etc. may be engraved in a front side of a tablet. However, due to a problem relating to visibility caused by this engraving, there has been an increasing need to make a print directly on a tablet by printing. Patent literatures 1 and 2 suggest techniques of printing on a tablet using an ink-jet printer.
According to the disclosure of patent literature 1, image of a plurality of works (tablets) supplied randomly is captured to detect information about each work such as a position and a posture, and a pattern of printing on each work is generated based on the detected work, information. According to the disclosure of patent literature 2, an image of a plurality of tablets supplied randomly is captured by a line sensor camera, and print data responsive to an orientation of a score line in a tablet is generated based on the resultant image data.